Re: Will the prize be won by the end of 2014? Posted on: Mon Jul 08, 2013 4:24 pm

OK, I was just curious. Now, back to the topic of this thread. Does anybody really think the prize will be won by the end of 2014? Three people have voted yes in the poll, but do you three actually believe this will happen? What's the basis of your yes votes? Is it just blind optimism, or do you know something about the progress of one of the teams that hasn't been published?

The front runners seem to be Prometheus and WikiSat. Prometheus hasn't shown any results of rocket tests, or even published a viable rocket design. So it seems like they are no where near to attempting an orbital launch, or even a space launch by the end of 2014.

WikiSat has done many interesting balloon and rocket motor tests. I'm sure they've learned quite a bit from their "Coke Zero" motors. However, it seems like they still have a long way towards developing a practical motor.

I think Rick Maschek has the best chance at winning the prize, but not before the end of 2014. He has a lot of high power rocket experience, and the work he's doing with the Sugar Shot team is impressive. I suggest that people visit the Sugar Shot site at http://sugarshot.org to see what a real amateur rocket project looks like.

And then there's the question of whether the cost restrictions are achievable. I don't think so, even if you only consider the cost of fuel and expendable materials used in the construction of unrecoverable components. This doesn't include the costs of boats and planes to recover the various booster stages that are needed to achieve orbit. I suppose it's possible that someone could use creative accounting methods to hide the real costs of the mission. That's the only way that I could see the cost restrictions being met.

Re: Will the prize be won by the end of 2014? Posted on: Mon Jul 08, 2013 9:03 pm

DaveHein wrote:

And then there's the question of whether the cost restrictions are achievable. I don't think so, even if you only consider the cost of fuel and expendable materials used in the construction of unrecoverable components. This doesn't include the costs of boats and planes to recover the various booster stages that are needed to achieve orbit. I suppose it's possible that someone could use creative accounting methods to hide the real costs of the mission. That's the only way that I could see the cost restrictions being met.

The rules seem to be quite clear on the cost aspect to me things like ground support insurance, clearance costs etc are not included so it is just the cost of what leaves the ground plus any extra energy costs(for instance a magnetic linear motor launcher on the ground might cost you a few £Million but if the electricity to launch and satellite cost under £1000 you could still win) and if any part of what leaves the ground is recovered and reusable then that can be subtracted on the reusable version tho I think it does include any refurbishment costs. Does that make you think it is more likely to be won at some point.

And Paul if you want us to think like Barnes-Wallis how about stretching a big sheet of graphene over the three peaks near where they tested the bouncing bombs and try trampling to space joking apart i do think the N-Prize is just about achievable under the rules given but i certainly think it will cost more than the Prize is worth to achieve it but any technology that does succeed will be worth considerably more anyway whether its an incremental betterment of current technologies or a new phase change technology. And the Prize does set out a set of parameters that focuses the mind sharply.

_________________Someone has to tilt at windmills.So that we know what to do when the real giants come!!!!

Re: Will the prize be won by the end of 2014? Posted on: Mon Jul 08, 2013 9:10 pm

Alex has the rules right. I'd also agree with him that a successful attempt is likely to cost more (in development and in non-budget expenditure) than the prize money.

As for the graphene trampoline, the good news is that you could probably bounce a sufficiently dense object into orbit that way, if you got the angles right. The bad news is that you'd probably have to drop it from way above orbital height

_________________"Gentlemen, we haven't got any money, so we are going to have to think!"

Re: Will the prize be won by the end of 2014? Posted on: Mon Jul 08, 2013 9:51 pm

I hadn't read the rules in a couple of years, and I had forgotten that the rules already incorporated "creative accounting".

I just can't believe that anyone who would go through the tremendous effort and expense to launch a satellite would go through the extra expense and effort to meet the N-Prize restrictions. In other words, it would cost them more to try to win the N-Prize than it would if they ignored the N-Prize.

Re: Will the prize be won by the end of 2014? Posted on: Mon Jul 08, 2013 11:05 pm

Paul H. Dear wrote:

Alex has the rules right. I'd also agree with him that a successful attempt is likely to cost more (in development and in non-budget expenditure) than the prize money.

As for the graphene trampoline, the good news is that you could probably bounce a sufficiently dense object into orbit that way, if you got the angles right. The bad news is that you'd probably have to drop it from way above orbital height

The other easier solution that would fit within the rules would be to dig an angled 120km hole at the centre point between the 3 peaks and pull the graphene sheet down to the bottom before releasing tho i think the ramblers association might object to a new mini volcano in a national park when the active cooling was switched off i think the Rockoon idea is much more feasible.

_________________Someone has to tilt at windmills.So that we know what to do when the real giants come!!!!

Re: Will the prize be won by the end of 2014? Posted on: Tue Jul 09, 2013 2:35 pm

Paul H. Dear wrote:

That's true. But then again, if you want to launch a very small satellite you can just buy a cubesat slot for $80K or so. That's not the point of the N-Prize, though.

So could I win the N-Prize if I paid someone $2000 to transport my 20 gram satellite in their 1Kg cubesat, and then eject it from the cubesat while in orbit? 20 grams is 2% of the mass of a cubesat, so it's share of the cost should be $1,600.

Re: Will the prize be won by the end of 2014? Posted on: Tue Jul 09, 2013 4:17 pm

That's too bad. The 20-gram satellite ejected from a cubesat would have been interesting. Maybe it's already been done. There are groups working on nano-sats. I think there's a group at Cornell working on it.

The problem with launching small satellites is the 1/R air drag effect. Air drag becomes less of an issue as payloads (and launch vehicles) become larger. This is because the frontal area scales as R squared, but the volume scales as R cubed. So the acceleration due to air drag is inversely proportional to the size.

Of course, the aerodynamic forces, rocket thrust and amount of fuel are huge for large rockets. However, the delta-v needed to overcome atmospheric drag is lower for large rockets.

It seems like the rockoon is the best approach for the N-Prize. It reduces the launch vehicle down to the size used in amateur rocketry. Maybe someone will attempt an amateur high power rockoon launch in the next few years.

Re: Will the prize be won by the end of 2014? Posted on: Tue Jul 09, 2013 4:32 pm

Agreed, drag on a 20g satellite at the lower limit of 100km is going to be an issue - that's one reason for stipulating only 9 orbits to qualify. Of course, people can also launch to higher orbits.

As a definite non-expert, I agree that rockoons (or at least air-launches) make a lot of sense. The scaling of aerodynamic drag on small rockets is a penalty relative to large rockets, and this goes away (partly) if you start from a higher altitude.

Paul

_________________"Gentlemen, we haven't got any money, so we are going to have to think!"

Re: Will the prize be won by the end of 2014? Posted on: Tue Jul 09, 2013 5:28 pm

That’s true with respect to drag, but not with respect to cost. Launching a small rocket at an altitude high enough to overcome the drag penalty is no small operation, no matter how you do it. Your choices are really either high-altitude balloon or high-altitude airplane. The more cost effective air-launch is probably from an airplane. With an airplane, theoretically, the only cost is fuel and you have much more precise control of launch bearing, timing and attitude.

The booster of a multistage rocket is in effect a high-altitude launch platform for the upper stage(s). If the booster costs less than launching from an airplane, especially likely if the booster is recoverable, than a surface launch makes the most sense.